commit b2375947777b7cc04c3f6745244e82418a6d66e6
author Adrian Roos <roosa@google.com> Fri Jan 19 22:31:28 2018 +0100
committer Adrian Roos <roosa@google.com> Tue Jan 23 15:06:50 2018 +0100
tree aa03ae429f18fe8e94fa040361f84bdef51179d4
parent a8c7794856c5794fa5b31cf5398b8f773650d6c7

FRP: Explicitly throw UnsupportedOperation when FRP is not supported

Changes KeyguardManager.createConfirmFactoryResetCredentialIntent such that
it throws UnsupportedOperationException when credential-based FRP is not
available on the device (either because storage was corrupted, or the device
simply does not support it).

This allows GMScore to distinguish this case from when the previous owner
simply didn't set up security.

Also fixes a few places where we previously unintentionally crashed with an
NPE.

Bug: 72368658
Test: atest LockSettingsStorageTests
Change-Id: I92fe1d4b06834e76a4bfffad41276ca28c68ce70

services/core/java/com/android/server/PersistentDataBlockService.java

diff --git a/services/core/java/com/android/server/PersistentDataBlockService.java b/services/core/java/com/android/server/PersistentDataBlockService.java
index 4298140..21093b9 100644
--- a/services/core/java/com/android/server/PersistentDataBlockService.java
+++ b/services/core/java/com/android/server/PersistentDataBlockService.java
@@ -28,6 +28,7 @@
 import android.os.UserManager;
 import android.service.persistentdata.IPersistentDataBlockService;
 import android.service.persistentdata.PersistentDataBlockManager;
+import android.util.Log;
 import android.util.Slog;
 
 import com.android.internal.R;
@@ -582,7 +583,12 @@
         @Override
         public boolean hasFrpCredentialHandle() {
             enforcePersistentDataBlockAccess();
-            return mInternalService.getFrpCredentialHandle() != null;
+            try {
+                return mInternalService.getFrpCredentialHandle() != null;
+            } catch (IllegalStateException e) {
+                Slog.e(TAG, "error reading frp handle", e);
+                throw new UnsupportedOperationException("cannot read frp credential");
+            }
         }
     };
 
@@ -638,7 +644,7 @@
         @Override
         public byte[] getFrpCredentialHandle() {
             if (!enforceChecksumValidity()) {
-                return null;
+                throw new IllegalStateException("invalid checksum");
             }
 
             DataInputStream inputStream;
@@ -646,8 +652,7 @@
                 inputStream = new DataInputStream(
                         new FileInputStream(new File(mDataBlockFile)));
             } catch (FileNotFoundException e) {
-                Slog.e(TAG, "partition not available");
-                return null;
+                throw new IllegalStateException("frp partition not available");
             }
 
             try {
@@ -662,8 +667,7 @@
                     return bytes;
                 }
             } catch (IOException e) {
-                Slog.e(TAG, "unable to access persistent partition", e);
-                return null;
+                throw new IllegalStateException("frp handle not readable", e);
             } finally {
                 IoUtils.closeQuietly(inputStream);
             }